http://api.tweetmeme.com/imagebutton.gif?url=http://sports.espn.go.com/nba/news/story?id=5200347&campaign=rss&source=NBAHeadlines (http://api.tweetmeme.com/share?url=http://sports.espn.go.com/nba/news/story?id=5200347&campaign=rss&source=NBAHeadlines&service=tinyurl.com&source=espn)The NBA is investigating an incident between referee Joe DeRosa and a fan at halftime of Tuesday's Game 2 of the Eastern Conference finals between Orlando and Boston.